Chapter 9
Know
-There are different lines of defenses.
-respiratory system
-Skin
-Digestive system
-circulatory system
-Air, water, food, and animal contact can pass pathogen.
-HIV is a deadly disease.

-What is a vaccine.
Want to Know
- How really HIV work.
- How did virus go through the membrane of the cell.
-What cause noninfectious disease.
- How allergy accrue.
Learned
- About what is cancer.
- How active immunity and passive immunity work.